The invention is particularly well suited for use in a process where the core is cured and hardened within the core box by CO.sub.2 gas which is circulated into contact with the sand mixture of the core after the mixture is compacted in the pattern of the core.
Generally, cores used in the casting of parts in a foundry, are formed by compacting a sand mixture into the core pattern of a core box. The compacted, but untreated core, is then separated from the pattern by shaking the core box with vibrators. Nextly, the core is placed in an oven in which the sand mixture is cured and hardened. The heat treatment of the cores, formed in this manner, is expensive and time consuming.
It has been found that the use of CO.sub.2 gas for hardening the cores within the core boxes, greatly speeds up this process. However, the foregoing method for stripping the cores from the core box does not work efficiently, and occasionally it becomes necessary to shutdown the process to remove, by hand, a hardened core that becomes stuck within the core box. The invention is directed to solving this particular problem.
Briefly stated, the invention is in a core box having a core pattern with a specially configured recess in which the core material is packed to form the core. The core box is provided with a self-contained mechanism for forcibly ejecting the core from the core box. This mechanism includes a plurality of ejector pins which are motivated into action by an inflatable bag, to physically engage the core and push it from the recess onto a rigid support or core board which is positioned for receiving the core. Thus, the cores are easily removed to provide a continuous CO.sub.2 process for making cores used in a foundry.